In dental field, it is one of key points to obtain an accurate 3D teeth model corresponding to clenched state during the course of treatment (for example, orthodontics). 3D camera system is used to create a 3D model of the teeth directly with the patient, which avoids the need to cast impressions and send them to the lab for restoration. This reduces cost and simplifies the workflow of dental restoration.
For the process of constructing global 3D teeth model, the step of bite registration is one of necessary and crucial steps. Bite registration is the process of registering the upper jaw with the lower jaw, which could establish a 3D spatial positioning relationship between an upper jaw and its corresponding, lower jaw in clenched state.
In an existing 3D camera system, during bite registration, only one bite surface is required for constructing a global 3D teeth model. In this method, the single bite surface is captured from one certain location (such as right side of molars) of the clenched teeth by a scanner, then the 3D teeth models of the upper jaw and the lower jaw captured independently are stitched onto the bite surface in a semi-automatic way so as to complete bite registering. However, when the global teeth contains a plurality of teeth (such as more than 5 teeth), the bite registration obtained from only one location of the bite surface may lead to significant mismatch in another location. For example, when only one bite surface corresponding to right side of molars is used, there are several hundreds microns of mismatch in the bite registration corresponding to the distant end (such as incisors or left side of molars). Thus, it is difficult to ensure the overall accuracy of bite registration, which results that a great difference may exist between the ultimate virtual global 3D teeth model constructed by this single bite registration and the actual global teeth in unique clenched state.
U.S. Pub. No.: US 2005/0196724A1 to Ross J. Miller et al. discloses a device for bite registration, which uses block (200) filled with impression material to record bite configurations. Evidently, it can not provide digital visual bite surface, and thus is not adaptable to digital 3D camera system.
Further, U.S. Pat. No. 8,121,718 B2 to Rüdger Rubbert et al, discloses an interactive orthodontic care system based on intra-oral scanning of teeth. In this system, when stitching both the upper jaw and the lower jaw onto the bite surface, it is completed in a manual way. Moreover, only one bite surface is used for obtaining a 3D virtual model of the teeth either.